Drop the Kubernetes manifests as static files clean up (this is only
needed for upgrades from 1.2.x).
Fix Talos handling of cgroup hierarchy: if started in container in a
non-root cgroup hiearachy, use that to handle proper cgroup paths.
Add a test for a simple TinK mode (Talos-in-Kubernetes).
Update the docs.
Fixes#8274
Signed-off-by: Andrey Smirnov <andrey.smirnov@siderolabs.com>
